Clusters containing multiple copies of the same sequence are used to enhance the signal intensity from the incorporation of nucleotides when sequencing by synthesis or the incorporation of oligonucleotides when using 2 base encoded sequencing, also called SOLiD (Sequencing by Oligonucleotide Ligation and Detection). This relies on the sequences being in-phase and the same nucleotide or oligonucleotide being incorporated onto each growing amplicon at the same time in the cluster. However, individual amplicons can become out-of-phase (dephasing) due to nucleotides or oligonucleotides being under- or over-incorporated. As sequencing progresses these accumulate and this reduces the accuracy of base calling.